The present invention relates to an elevating apparatus for lifting workers, materials and/or pieces of equipment to an elevated position to provide a safe and stable work platform for various operations at desired elevation on bridges, multistory buildings, or other high constructions.
Recent years have found various high constructions such as bridges, multistory buildings, or other structures. It is frequently necessary to lift workers or materials from the ground to an elevated position on such high constructions, or provide a safe work platform at desired elevation for various operations such as tightening of bolts or painting on the underside of a bridge or applying a floor material to a higher floor in a building. Various lifting or elevating apparatus have been developed and used. One common problem with the known arrangements is that the work platform as it is lifted to an elevated position is unstable and liable to swing due to winds, making the workers feel insecure and preventing them from doing desired works. The work platform can be supported stably against unwanted wobbling movements by a rugged and heavy mechanism for lifting the platform or an additional mechanism for reinforcing the platform. However, these mechanisms are complex in construction, result in an additional cost, and cannot be transported easily. There is known a manual support arrangement in which a plurality of ropes ar attached to an elongated ladder-like mechanism supporting thereon a work platform and manually pulled in opposite directions to render the platform stable against wobbling motions. Although the ladder-like platform supporting mechanism is relatively lightweight and thin in construction, several workers are required just for pulling and gripping the ropes. Accordingly, the known manual support apparatus has failed to find widespread general use.